Analyzation of the Trend in Torque Deterioration of the 775pro Motor

Direct current motors are widely used in FIRST robotics and none can outperform the 775pro. Its compact design coupled with its fantastic torque to speed ratio make it the optimal motor choice for most teams. However, no matter how great a motor is, it will eventually start to fail, which led to the reason for conducting this experiment: finding exactly when to switch a motor.

The purpose of this experiment was to determine how the motors torque output declined over heavy use. In order to find the trend of deterioration, motors were run to stall torque, the torque where the motors rotational speed becomes zero, cooled, and run again until the motor failed, in this case mechanically. The hypothesis stated that torque would decline at an exponential rate. To test this hypothesis regression models were found for each data set. A least squares regression line ended up fitting the data best however the lines had slopes nearing zero indicating little to no decline in the overall torque output. Due to the data having a horizontal slope, the hypothesis was rejected. Even though it was concluded that torque did not decline, it was found that the brushes on the motor would fail after approximately 100 trials. In summary, when looking for when to switch a motor based on torque deterioration, it was found that the motor brush will break before the torque declines at all, after approximately 100 instances of stall torque. This means that there is no reason to switch a motor before it reaches its breaking point.

Research Conducted By:

Noah Banick
Cousino High School

Connor Zagumny
Lake Shore High School